Phase Difference Element Anti-Reflection Film Group
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Solution Overview
Problem
Phase difference elements using obliquely vapor deposited films face significant reflection issues due to the differential refractive indices between the vapor deposited film and the glass or quartz substrate, leading to reduced durability and optical performance.
Innovation Solution
A phase difference element is designed with a transparent substrate and an obliquely vapor deposited multi-layer film, accompanied by an interface anti-reflection film group composed of alternately high and low refractive index films, deposited between the substrate and the vapor deposited film, with refractive indices optimized to reduce reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high refraction index substance such as Ta2O5, ZrO2 or TiO2 is used as the material for vapor deposition, then the phase difference element becomes highly resistive against light and heat, but reflection of incident light occurs on the substrate/vapor deposited film interface due to marked differential in refraction index
Solution Approach 1:
An interface anti-reflection film group is introduced as an intermediary layer between the transparent substrate and the obliquely vapor deposited film. This intermediate layer has a refractive index that is higher than the substrate but lower than the vapor deposited film, serving as a refractive index bridge to reduce reflection at the interface while maintaining the protective properties of the high refraction index material.
Solution Approach 2:
The phase difference element is constructed as a composite structure combining multiple materials: the transparent substrate, the interface anti-reflection film group with specific refractive index properties, and the obliquely vapor deposited film with high refraction index. This composite structure integrates the advantages of each material while mitigating their individual disadvantages.
2Manufacturing precision
If the refractive index of the vapor deposited film is significantly higher than the substrate, then the phase difference element achieves desired optical properties, but the durability and optical performance are reduced due to reflection
Solution Approach 1:
The interface anti-reflection film group acts as a mediator that allows the high refraction index vapor deposited film to maintain its optical properties for phase difference control while preventing the harmful reflection effects that would otherwise compromise durability and performance.
3Ease of manufacture
If an obliquely vapor deposited film is used to set desired phase difference value and increase surface area, then cost is reduced by volume production and resistance against light and heat is increased, but reflection of incident light occurs due to refraction index differential
Solution Approach 1:
The interface anti-reflection film group is deposited as an intermediate layer during the manufacturing process, enabling the obliquely vapor deposited film to achieve cost reduction and surface area increase benefits while the intermediate layer manages the reflection issue through its optimized refractive index.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively minimizes light reflection and enhances optical characteristics, improving the durability and performance of the phase difference element by matching refractive indices and reducing incident light reflection.
Implementation Method 1
The refractive index of the interface anti-reflection film group is higher than the refractive index of the transparent substrate and lower than that of the obliquely vapor deposited film
Implementation Method 2
an interface anti-reflection film group composed by one or more of alternately high and low refractive index films stacked between the transparent substrate and the obliquely vapor deposited film
Implementation Method 3
The layers of the dielectric material are alternately vapor deposited from two directions differing by 180° from each other
Data Source
AI summary
A phase difference element capable of reducing reflection of incident light and a manufacturing method for the phase difference element are disclosed. The phase difference element includes a transparent substrate 11, an interface anti-reflection film group 12 and an obliquely vapor deposited film 13. The interface anti-reflection film group is composed by one or more of alternately high and low refractive index films, with the film thicknesses of the respectively films being equal to or less than the wavelength of light in use. The obliquely vapor deposited film is formed by a plurality of layers of a dielectric material. These layers are alternately obliquely vapor deposited from two directions differing by 180° from each other. The refractive index of the interface anti-reflection film group 12 is higher than the refractive index of the transparent substrate 11 and lesser than that of the obliquely vapor deposited film 13.